[gfortran] Exponentiation by integral exponents

[Tobias Schlüter]

Paul Brook wrote:
> 
>>       rse.expr = convert (type, rse.expr);        // second try
> 
> 
> This is correct. You should then just fall through to the BT_REAL case.
> 
Thanks.

I found the bug which made my test fail: My problem was due to the fact 
that my testcase was trying to exponentiate a complex variable. This of 
course failed, because it unconditionally falls through to the real 
case, even though rse.expr has just been converted to a complex type. 
I'll let this as is, as I only want to try the builtin for the moment.

Now I have to find out, how to correctly use the builtin. Simply 
replacing "pow" by "__builtin_pow" in trans-decl.c didn't work, the 
compiler generates a call to __builtin_pow in the assembly, which is not 
what I want.

BTW I just sent my signed copyright papers to the FSF.

- Tobi